Hemiballismus as a complication of an intratumoral chemotherapy catheter

We report an unusual case of delayed bilateral, right greater than left hemiballismus in a 15-year-old female patient with a history of a craniopharyngioma 2years following the insertion of a right intratumoral chemotherapy catheter. Following cyst decompression, the catheter was found to have changed position, traversing the basal ganglia structures, namely the right subthalamic nucleus. Her movement disorder near-completely resolved immediately following removal of the catheter. A review of the current literature and proposed pathophysiological mechanisms are discussed.